Seeking DDI Scientific Board nominations

The DDI Alliance is soliciting nominations for members of the recently restructured DDI Scientific Board.  Nominations may be sent directly to Jared Lyle, Executive Director, DDI Alliance (  Please submit your nominations by 7 December 2020.  In early December, the Alliance membership will elect the members of the Scientific Board.
The purposes of the Scientific Board are to:
  • Provide direction and coordination in the development of the substantive content of the DDI standards and other work products of the Alliance by its sub-committees and working groups within the context of the Alliance Strategic Plan.
  • Implement the scientific work plan agreed at the Annual Meeting of the Scientific Community.
  • Oversee the substantive content of DDI standards and other work products.
  • Undertake research and testing concerning proposals for DDI standards and other work products.
  • Develop and promulgate best practices for use of DDI standards and work products.
  • Assess progress and barriers to progress.
  • Provide a report on progress of the scientific work plan over the previous year, and proposals for the future scientific direction and related activities to the Annual Meeting of the Scientific Community.
The restructured Scientific Board will be composed of seven voting members elected by the Members of the Alliance.  For the initial election, three will be elected for two-year terms and four for four-year terms; all terms will start 1 January 2021 and run through 30 June of their respective term periods.  The Executive Director and Chair of the Technical Committee shall serve as ex‐officio members, without internal vote, of the Scientific Board. Representatives from Members and Associate Members of the Alliance are eligible to serve as elected members of the Scientific Board.  A majority of the elected members of the Scientific Board must be from Member Organizations.  

DDI Bylaws amendments approved

In September and October, DDI members voted on proposed amendments to the DDI Bylaws about a restructuring of the DDI Scientific Board, which is the scientific and technical body of the Alliance.  Twenty-one of the 28 eligible voting designated member representatives voted "Yes", one voted "I formally decline to vote", and six did not respond.  The vote passed with a two-thirds majority, which means the Bylaws amendments are adopted.  
These changes were proposed by a temporary working group composed of DDI member representatives, discussed at the 2020 annual Meeting of Members, and subsequently distributed to the entire membership for comments and further edits.  We especially thank the temporary working group, chaired by Ingo Barkow, that drafted and proposed the Bylaws amendments. 
To view the updated Bylaws, please visit:

Registration for EDDI 2020 is now open

Registration for the Virtual European DDI Conference EDDI 2020 is now open, at
Registration is open until Wednesday 25th 2020 23:59. 

The conference will take place on 1/2 December 2020, and workshops and tutorials will also be held on 30 November 2020.
The full program is available at: All times are CET.

Links to participate in the virtual Conference will be sent to participants on Thursday November 26th 2020.

Mari Kleemola & Jon Johnson 
EDDI 2020 Co-Chairs

Structured Data Transformation Language (SDTL) Vote

Dear DDI Alliance community,

We are ready to vote on Version 1.0 of SDTL (Structured Data Transformation Language) for publication. Next week, Designated Member Representatives will receive a link to cast their votes. It is important to vote; a two-thirds majority is required for approval. 

SDTL is a new product for DDI and we are asking you to approve its inclusion in the product line of the DDI Alliance. Over the past year this product has provided the Technical Committee with:

  • Statement of content and functionality
  • Information on the business case for the product
  • Objectives for the product
  • Position within the suite of products supported by the DDI Alliance
  • A maintenance plan for the product

The public review was completed between July 1 through August 31, 2020. All issues have been addressed and the product prepared for the final vote on publication.

To assist you in evaluating this product for inclusion in the suite of DDI products a webinar will be presented on

Monday, November 2, 2020 at 10:00 Eastern Time (16:00 European Time)
To join the Webinar:

Meeting ID: 820 4137 8650
Find your local number:

The following content should also be informative:

SDTL is an independent language for representing data transformation commands in statistical analysis packages, such as SPSS, Stata, SAS, R, and Python.  Commands like RECODE, MERGE FILES, and VARIABLE LABELS are rendered in a structured format (JSON, XML, RDF) that is easy for machines to read and process.  Command scripts translated into SDTL produce variable-level data transformation histories, which can be translated into natural language.  SDTL can be added to Data Documentation Initiative (DDI) and other metadata standards for use in data catalogs, codebooks, and other documentation.  

We wish to thank George Alter and the SDTL Working Group, as well as the Technical Committee, for the preparation of the SDTL product for publication.

Structured Data Transformation Language (SDTL) Webinar: 2 November

The Structured Data Transformation Language (SDTL) Working Group of the DDI Alliance will host a Webinar on 2 November at 10am Eastern Time to explain the value of SDTL to the DDI community.  SDTL is a new tool for creating machine actionable data provenance.  The webinar will describe SDTL and explain how it works with DDI.

SDTL is an independent language for representing data transformation commands in statistical analysis packages, such as SPSS, Stata, SAS, R, and Python.  Commands like RECODE, MERGE FILES, and VARIABLE LABELS are rendered in a structured format (JSON, XML, RDF) that is easy for machines to read and process.  Command scripts translated into SDTL produce variable-level data transformation histories, which can be translated into natural language.  SDTL can be added to Data Documentation Initiative (DDI) and other metadata standards for use in data catalogs, codebooks, and other documentation.  

To join the Webinar:

Meeting ID: 820 4137 8650
Find your local number:

New Paper: DDI-Lifecycle Facilitates Cross-Study Linking of Cognitive Data

The National Archive of Computerized Data on Aging (NACDA), located within ICPSR, has published a working paper that describes a methodology that used DDI Lifecycle tools to identify and organize health questions and measures related to Alzheimer’s and other cognitive impairments using data maintained or supported by NACDA. This project specifically used the National Social Life, Health and Aging Project (NSHAP) and the National Health and Aging Trends Study (NHATS) as the comparison proof of concept.

The methodology used in this process identifies variables that measure Alzheimer’s disease (A.D.) and other cognitive impairments within NSHAP and NHATS, as well as sociodemographic and comorbidity data commonly associated with increased risk of A.D. and other cognitive impairments. The project generated enhanced metadata using DDI Lifecycle software to make the discovery of A.D. and other cognitive impairments variables more straightforward and increase the user-friendly elements of these studies. Finally, the proposed supplement included the creation of a customized bibliography of the use of NSHAP and NHATS data in the analysis of A.D. and other cognitive impairments research, allowing researchers to more easily review the existing body of literature using these data resources. 

Webinars: Data Description with DDI-CDI

The Data Documentation Initiative Alliance recently announced the public review of the new specification, DDI – Cross Domain Integration (DDI-CDI). In order to introduce potential reviewers to the specification, a series of general introductory webinars have been held. Perhaps you already took part in one of them or would like to have a look at them? Please review the slides and recordings.

To follow up on this, we are now launching a second series of virtual events 1) for specific audiences, and 2) about specific topics.

We are writing to you to invite you to an event focusing on data description with DDI-CDI, which will be held on Wednesday 12th August at 14:00 UTC and we plan to host a follow-up workshop, a week later, to allow more detailed discussion on 19th August 2020 at 14:00 UTC. Attendees are asked to register using the following links:

Presentation and discussion, 12 August:

Discussion workshops, 19 August:

The webinar on data description focuses on:

  • understanding the meaning of data;
  • cross-domain exchange;
    • harmonization, including e.g. the same measurement represented in different data structures, and
    • different measurements are being compared;
  • transformation across structures and platforms


DDI-CDI is a model-driven specification that is designed to provide support for the wide number of use cases that use data from multiple sources and domains. It originates from the  Social, Behavioral, and Economic (SBE) sciences, but is designed to be applicable to data coming from any domain. Integrating data across domain and disciplinary boundaries requires a flexible mechanism for describing disparate data sources, and their provenance and processing. DDI-CDI is designed to meet these emerging needs for the integration of data in old and new forms, coming from a variety of domains.

Cross Domain (Data) Integration is particularly important for grand challenge research areas that necessarily combine data of many types. CODATA sees great potential in DDI-CDI as a contribution to the International Science Council-endorsed Decadal Programme ‘Making Data Work for Cross-Domain Grand Challenges’. Consequently, CODATA through the Decadal Programme will partner with DDI in the public review process, assisting in getting feedback.

DDI-CDI aims to be technology agnostic and to be adaptable to any platform or representation. At the moment the DDI-CDI specification is provided as a formal UML model and as an XML syntax representation of that model: we are keen to adapt it to other technologies and representations, including RDF, JSON, Python etc.

Some resources:

To prepare for the event

At the event, data description using DDI-CDI will be introduced, followed by a structured discussion between the audience and people from the DDI-CDI team, with the event lasting for an hour. Please take a look at the draft presentation.

We would also kindly ask you to think about the following questions in advance of the event:

  • Are there data structures that you commonly use that we don’t seem to have covered?
    • What are they?
    • Do you see potential in DDI-CDI for needs that you currently haven’t met?
  • What have we missed?

We are looking forward to meeting you at the events!


Joachim Wackerow
Chair, DDI Alliance Scientific Board

DDI work products listed in FAIRsharing

Did you know that DDI work products are listed in FAIRsharing, a curated resource on data and metadata standards.  DDI work products cataloged in FAIRsharing include:

FAIRsharing is used by curators, librarians, developers, societies, funders, and researchers to explore what standards, databases, repositories, and data policies exist and are interrelated.

Feedback Requested: Scientific Board restructuring proposal

A temporary working group has been meeting since February to discuss how to improve the structure and organization of the Scientific Board, which is the scientific and technical body of the Alliance.  This past week, that group finalized their recommendations to propose a restructuring and to draft changes to the Alliance Bylaws.  Those recommendations are here:

The recommendations include:

  • ScientificBoard restructuring.docx.  This short note is intended to explain the thinking behind a new plan to organize, operate, and engage with the Scientific Board of the DDI Alliance.
  • Bylaws-2020-Final_Draft-20200619.docx.  This contains the proposed changes to the DDI Alliance Bylaws to accommodate the reorganized Scientific Board.
  • ScientificBoardOperationalGuidelines-draft.docx.  This specifies the operational guidelines of the reorganized Scientific Board.

As a next step, we ask that you review the recommendations and send any comments to Ingo Barkow <>, chair of the temporary working group, by 17 July.  

Ingo and the temporary working group will finalize their recommendations and then send them to the Executive Board, which under the Bylaws can propose amendments.  "Amendments must be adopted by a two‐thirds majority vote of the Designated Member Representatives after written electronic notice of the vote of at least sixty days" (DDI Alliance Bylaws, (Section XVII).  

Public Review: Structured Data Transformation Language (SDTL)

The DDI Alliance is pleased to announce the Public Review of Structured Data Transformation Language (SDTL), a new product in the DDI suite of products that provides a key component of an automated metadata production process.
SDTL is an independent intermediate language for representing data transformation commands.  Statistical analysis packages (e.g., SPSS, Stata, SAS, and R) provide similar functionality, but each one has its own language and syntax.  SDTL consists of JSON schemas for common operations, such as RECODE, MERGE FILES, and VARIABLE LABELS.  SDTL provides machine-actionable descriptions of variable-level data transformation histories derived from any data transformation language.  Provenance metadata represented in SDTL can be added to documentation in Data Documentation Initiative (DDI) and other metadata standards.

SDTL greatly enhances the value of DDI; currently, DDI metadata is almost always created by data repositories but not by data producers.  Even when data are born digital, data producers discard provenance information that could be transported into DDI, because they perform data management and variable transformations in statistical packages that offer minimal metadata capabilities.  SDTL and the tools created by the C2Metadata Project are designed to create a metadata life cycle that parallels the research data life cycle. The same scripts that are used to transform and manage variables and data files can be used to update metadata files.  As a result, data producers can create more accurate and complete DDI metadata with less time and effort for them and for data repositories.

Links to the specification and instructions for comment are found at  We are eager to obtain feedback from a broad community on this specification. The comment period is open until August 31, 2020, and we hope to hear from you. Comments are requested on the content and scope of the:

  • SDTL Command Language
  • Function Library
  • Pseudo-Code Library
  • Documentation